A few days ago, Microsoft released the long-awaited Windows Phone 7.8 update for all those users who will be stuck on Windows Phone 7 forever because there's no upgrade path to Windows Phone 8 other than buying a new phone. Now that it's here, what, exactly, does WP7.8 to the table?

We can get into all sorts of pedantic definitions of what a kernel is or constitutes. But from the points of view of the end user and developer, Microsoft has released 3 different somewhat incompatible phone OSs in less than 4 years.

That the last iteration of incompatibility is due to different kernel families involved, an event that apparently only happens "once in a lifetime," becomes sort of moot.

We can get into all sorts of pedantic definitions of what a kernel is or constitutes.

Not really. The OS kernel is pretty well defined in the world of OS development. The kernel is the underlying component that coordinates the rest of the OS. The OP was correct, MS have changed the OS kernel exactly once (i.e. CE to NT) in the lifetime of Windows Phone (all Windows phone, since the first Windows CE based phone OS.) They have iterated on the kernel version, yes, but then so does every OS release.

What you are complaining about it the "window dressing" that makes the kernel and its services do something useful for the end user.

At the end of the day, Windows CE had a good run. It went through countless revisions - I remember using it on devices when it looked like a cut down version of Windows 98 (and they were still creating versions of that OS till recently, as a bunch of ARM based cheapo netbooks used it, plus a lot of industrial use handhelds that we used to use in the sector I was employed in at the time.) The PocketPC OS was then a revision to make the OS more "Palm" like. That went from the original through around 4 or 5 major revisions, including phone use. Then we got the Windows Phone 7 etc. (probably Zune fits in there somewhere too...)

Anyway, I'll go back to writing the interface a contractor quoted 10 days and £7k for implementing for 2 products on Thursday, and which I've implemented in 1 and a bit days for all products... I therefore predict my time is worth something like 7x his and I've just wasted a few hundred correcting you.. lol.